Polymer dispersions and their uses

ABSTRACT

This invention relates to polymer dispersions prepared by the in situ polymerization of an ethylenically unsaturated monomer or mixture of monomers in a chain extender in the presence of a free radical polymerization initiator and a polyamide stabilizer. 
     The invention also relates to mixtures of the polymer dispersions with compounds having two or more active hydrogen atoms as determined by the Zerewittinoff method. These mixtures are used to prepare polyurethane products.

This is a division of application Ser. No. 460,312, filed Jan. 24, 1983,now U.S. Pat. No. 4,458,050.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to polymer dispersions and their uses. Thedispersions are prepared by the in situ polymerization of anethylenically unsaturated monomer in a chain extender in the presence ofa free radical polymerization initiator and a polyamide having a pendentamide group. They are used to blend with active hydrogen-containingcompounds to prepare polyurethane products.

2. Description of the Prior Art

One of the challenges faced by those working to improve products madefrom polyurethane polymers is to develop products which have acceptablemechanical properties, but which can be easily processed.

It is known that the mechanical properties of polyurethane products canbe improved by the use of graft polymer dispersions such as thosedescribed in U.S. Pat. Nos. Re. 28,715 and 29,014. It is also known thatthe mechanical properties of polyurethane elastomers can be improved ifchain extenders such as low molecular weight diols are added to theformulation. The chain extender is usually added to the graft polymerdispersion before reacting with the organic polyisocyanate. The problemwith this approach is that the chain extender is often not compatiblewith the polyol and results in phase separation of the graft polymerdispersion and chain extender. Moreover, the resulting compositionsoften have an unacceptable viscosity which makes processing difficult.

SUMMARY OF THE INVENTION

This invention relates to polymer dispersions prepared by the in situpolymerization of an ethylenically unsaturated monomer or mixture ofmonomers in a chain extender in the presence of a free radicalpolymerization initiator and a polyamide stabilizer having a pendentamide group.

The invention also relates to mixtures of the polymer dispersions withcompounds having two or more active hydrogen atoms as determined by theZerewittinoff method. These mixtures are used to prepare polyurethaneproducts.

The polymer dispersions are particularly useful because of their lowviscosities and the presence of the chain extender. They are readilycompatible with compounds containing two or more active hydrogen atoms.Consequently, their use in the preparation of polyurethane elastomers byreaction injection molding (RIM) is expected to offer advantages inprocessing.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

As was mentioned, the polymer dispersions are prepared by the in situpolymerization of an ethylenically unsaturated monomer or mixture ofmonomers in a chain extender in the presence of a free radicalpolymerization initiator and a polyamide stabilizer having a pendentamide group. The polymerization may be carried out at a temperaturebetween 40° C. and 160° C., preferably 100° C. to 125° C.

Ethylenially unsaturated monomers which can be used to prepare thepolymer dispersions include butadiene, isoprene, 1,4-pentadiene,1,5-hexadiene, 1,7-octadiene, styrene, alpha-methylstyrene,4-methylstyrene, 2-methylstyrene, 3-methylstyrene, 2,4-dimethylstyrene,ethylstyrene, isopropylstyrene, butylstyrene, phenylstyrene,cyclohexylstyrene, benzylstyrene, and the like; substituted styrenessuch as chlorostyrene, 2,5-dichlorostyrene, bromostyrene, fluorostyrene,trifluoromethylstyrene, iodostyrene, cyanostyrene, nitrostyrene,N,N-dimethylaminostyrene, acetoxylstyrene, methyl-4-vinylbenzoate,phenoxystyrene, p-vinyldiphenyl sulfide, p-vinylphenyl oxide, and thelike; the acrylic and substituted acrylic monomers such asacrylonitrile, acrylic acid, methacrylic acid, methylacrylate,2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, methylmethacrylate, cyclohexyl methacrylate, benzyl methacrylate, isopropylmethacrylate, octyl methacrylate, methacrylonitrile, methylalpha-chloroacrylate, ethyl alpha-ethoxyacrylate, methylalpha-acetaminoacrylate, butyl acrylate, 2-ethylhexyl acrylate, phenylacrylate, phenyl methacrylate, alpha-chloroacrylonitrile,N,N-dimethylacrylamide, N,N-dibenzylacrylamide, N-butylacrylamide,methacrylyl formamide, and the like; the vinyl esters, vinyl ethers,vinyl ketones, etc., such as vinyl acetate, vinyl chloroacetate, vinylalcohol, vinyl butyrate, isopropenyl acetate, vinyl metacrylate, vinylmethoxyacetate, vinyl benzoate, vinyl iodide, vinyltoluene,vinylnaphthalene, vinyl bromide, vinyl fluoride, vinylidene bromide,1-chloro-1-fluoroethylene, vinylidene fluoride, vinyl methyl ether,vinyl ethyl ether, vinyl propyl ethers, vinyl butyl ethers, vinyl2-ethylhexyl ether, vinyl phenyl ether, vinyl 2-methoxyethyl ether,methoxybutadiene, vinyl 2-butoxyethyl ether, 3,4-dihydro-1,2-pyran,2-butoxyl-2'-vinyloxy diethyl ether, vinyl 2-ethylmercaptoethyl ether,vinyl methyl ketone, vinyl ethyl ketone, vinyl phosphonates such asbis(betachloroethyl)-vinyl-phosphonate, vinyl phenyl ketone, vinyl ethylsulfide, vinyl ethyl sulfone, N-methyl-N-vinyl acetamide,N-vinylpyrrolidone, vinyl imidazole, divinyl sulfide, divinyl sulfoxide,divinyl sulfone, sodium vinylsulfonate, methyl vinylsulfonate, N-vinylpyrrole, and the like; dimethyl fumarate, dimethyl maleate, maleic acid,crotonic acid, fumaric acid, itaconic acid monomethyl itaconate,t-butylaminoethyl methacrylate, dimethylaminoethyl methacrylate,glycidyl acrylate, allyl alcohol, glycol monoesters of itaconic acid,dichlorobutadiene, vinyl pyridine, and the like. Any of the knownpolymerizable monomers can be used and the compounds listed above areillustrated and not restrictive of the monomers suitable for use in thisinvention.

Preferably used as acrylonitrile, styrene, and mixtures thereof inweight ratios of acrylonitrile to styrene of 3:1 to 1:3.

The chain extenders which are used to prepare the dispersions havemolecular weights of less than 400, preferably of 62 to 300, andpreferably have 2 active hydrogen atoms. Examples of chain extendersinclude aliphatic and/or araliphatic diols having 2 to 14, preferably 2to 6 carbon atoms such as ethylene glycol, 1,6-hexanediol andbis-(2-hydroxyethyl)hydroquinone 1,10-decanediol, diethylene glycol,dipropylene glycol and preferably 1,4-butanediol.

Preferably used, however, are 1,4-butanediol and ethylene glycol, andother chain extenders in which the polyamide stabilizer is soluble.Generally, the weight percent of vinyl polymer is from 10 percent to 70percent, preferably 40 percent to 50 percent based upon the total weightof the dispersion.

The stabilizer which is used to prepare the subject dispersions is apolyamide having a pendent amide group and an average molecular weightof about 5,000 to about 1,000,000, preferably from about 10,000 to about60,000. Preferably used as the polyamide is poly(N-vinyl-2-pyrrolidone).However, other polyamides having a pendent amide group prepared by thevinyl polymerization of olefinically unsaturated monomers such as vinylcaprolactam, acrylamide, and methacrylamide may be used. Thesepolyamides having a pendent amide group may also be prepared by othermethods known to those skilled in the art. The amount of stabilizer usedis such that the weight ratio of monomer to polyamide is from about 2:1to about 100:1, preferably about 16:1.

Free radical polymerization initiators which can be used to carry outthe polymerization reaction include, for example, the peroxides,persulfates, perborates, percarbonates, azo compounds, etc., includinghydrogen peroxide, dibenzoyl peroxide, acetyl peroxide, benzoylhydroperoxide, t-butyl hydroperoxide, di-t-butyl peroxide, lauroylperoxide, butyryl peroxide, diisopropylbenzene hydroperoxide, cumenehydroperoxide, paramenthane hydroperoxide, diacetyl peroxide,di-alpha-cumyl peroxide, dipropyl peroxide, diisopropyl peroxide,isopropyl-t-butyl peroxide, butyl-t-butyl peroxide, dilauroyl peroxide,difuroyl peroxide, bis(triphenylmethyl)peroxide,bis(p-methoxybenzoyl)peroxide, p-monomethoxybenzoyl peroxide, rubeneperoxide, ascaridol, t-butyl peroxybenzoate, diethylperoxyterephthalate, propyl hydroperoxide, isopropyl hydroperoxide,n-butyl hydroperoxide, t-butyl hydroperoxide, cyclohexyl hydroperoxide,trans-decalin hydroperoxide, alpha-methylbenzyl hydroperoxide,alpha-methyl-alpha-ethyl benzyl hydroperoxide, tetralin hydroperoxide,triphenylmethyl hydroperoxide, diphenylmethyl hydroperoxide,alphaalpha'-azo-2-methyl butyronitrile, alpha,alpha'-azo-2-methylheptonitrile, 1,1'-azo-1-cyclohexane carbonitrile, dimethylalpha,alpha'-azoisobutyrate, 4,4'-azo-4-cyanopentanoic acid,azobis(isobutyronitrile), 1-t-amylazo-1-cyanocyclohexane, persuccinicacid, diisopropyl peroxy dicarbonate,2-t-butylazo-2-cyano-4-methylpentane and the like; a mixture ofcatalysts may also be used. Azobis(isobutyronitrile) and2-t-butylazo-2-cyano-4-methylpentane are the preferred catalysts.Generally, from about 0.5 percent to about 10 percent, preferably fromabout 1 percent to about 4 percent, by weight of catalyst based on theweight of the monomer will be employed in the process of the invention.

The resulting dispersions have low viscosities, generally less than 1700cps at 25° C. This makes them particularly useful for processing byreaction injection molding techniques. The dispersions are preferablymixed with a compound having an average equivalent weight of 500 to10,000 containing two or more active hydrogen atoms as determined by theZerewitinoff method. Such mixtures appear to be homogeneous and maintainthis appearance for at least two days. Examples of compounds whichcontain two or more active hydrogen atoms include, but are not limitedto hydroxyl-terminated polyesters; polyoxyalkylenepolyether polyols;graft polyoxyalkylenepolyether polyols; alkylene oxide adducts oforganic compounds having at least two reactive hydrogen atoms such asamines and thiols; and hydroxy terminated acetals. These compounds willnow be more specifically described.

Any suitable hydroxy-terminated polyester may be used such as areobtained, for example, from the reaction of polycarboxylic acids ofpolycarboxylic acid anhydrides and polyhydric alcohols. Any suitablepolycarboxylic acid may be used in the preparation of hydroxy-terminatedpolyesters such as succinic acid, glutaric acid, adipic acid, pimelicacid, suberic acid, azelaic acid, sebacic acid, brassylic acid, thapsicacid, maleic acid, fumaric acid, glutaconic acid, α-hydromuconic acid,β-butyl-α-ethyl-glutaric acid, α,β-diethylsuccinic acid, phthalic acid,isophthalic acid, terephthalic acid, hemimellitic acid, and1,4-cyclohexanedicarboxylic acid. Anhydrides such as phthalic,tetrachlorophthalic, tetrabromophthalic, maleic, and1,4,5,6,7,7-hexachloro-bicyclo-(2,2,1)-5-heptane-2,3-dicarboxylic acidanhydride also may be used in the preparation of the hydroxy-terminatedpolyesters. Any suitable polyhydric alcohol, including both aliphaticand aromatic, may be reacted with the polycarboxylic acid orpolycarboxylic acid anhydride to prepare the hydroxy-terminatedpolyesters. Representative examples include ethylene glycol,1,3-propanediol, 1,2-propane glycol, 1,4-butanediol, 1,3-butanediol,1,2-butane glycol, 1,5-pentanediol, 1,4-pentanediol, 1,3-pentanediol,1,6-hexanediol, 1,7-heptanediol, 2-butene-1,4-diol glycerol,1,1,1-trimethylolpropane, 1,1,1-trimethylolethane, hexane-1,2,6-triol,α-methyl glucoside, pentaerythritol, and sorbitol. Also included withthe term "polyhydric alcohol" are compounds derived from phenoliccompounds such as 2,2-bis(4-hydroxyphenyl)propane, commonly known asBisphenol A and hydroxyalkyl ethers of such phenolic compounds such asbis-2-hydroxyethyl ether of hydroxyquinone, and the alkylene oxideadducts of the abovenamed polyhydric alcohols.

The hydroxy-terminated polyester may also be a polyester amide such asis obtained by including some amine or amino alcohol in the reactantsfor the preparation of the polyesters. Thus, polyester amides may beobtained by condensing an amino alcohol such as ethanolamine with thepolycarboxylic acids set forth above, or they may be made using the samecomponents that make up the hydroxy-terminated polyester with only aportion of the components being a diamine such as ethylenediamine. Thehydroxy-terminated polyester may also be a hydroxy-terminatedpolycaprolactone polyol.

Polyoxyalkylene ether polyols are preferably used as the polyol. Thesecompounds are prepared by reacting an alkylene oxide with a polyhydricalcohol. Any suitable polyhydric alcohol may be used in the preparationof the polyoxyalkylene polyether polyol, such as those disclosed abovefor use in the preparation of the hydroxy-terminated polyesters. Anysuitable alkylene oxide may be reacted with the polyhydric alcohol toprepare the polyoxyalkylene polyol. Representative examples includeethylene oxide, propylene oxide, butylene oxide, amylene oxide, styreneoxide, or mixtures thereof. Polyoxyalkylene polyols derived from two ormore oxides may possess either block or heteric structure. In additionto polyoxyalkylene polyols, other compounds such as polyols derived fromtetrahydrofuran and alkylene oxide-tetrahydrofuran mixtures may be used.The polyoxyalkylene polyether polyols preferably have primary hydroxylgroups, but may have secondary hydroxyl groups, and preferably, arepolyethers prepared from alkylene oxides having from two to six carbonatoms such as polyethylene ether glycols, polyoxypropylene ether glycolsand polyoxybutylene ether glycols. The polyoxyalkylene polyether polyolsmay be prepared by any known process such as, for example, the processdisclosed by Wurtz in 1859 and in Encyclopedia of Chemical Technology,Vol. 7, pp. 257-262, published by Interscience Publishers, Inc. (1951),or the process disclosed in U.S. Pat. No. 1,922,459. Alkylene oxideadducts of Mannich condensation products are also useful in theinvention.

In addition to the polyoxyalkylene polyether polyols just described,graft polyoxyalkylene polyether polyols may also be used in thepreparation of the reactive polyol composition. These polyols areprepared by the in situ polymerization of a vinyl monomer or monomers ina reactive polyol medium and in the presence of a free radicalinitiator. The reaction is generally carried out at a temperatureranging from about 40° C. to 150° C. A more comprehensive discussion ofthe graft polyols and their method of preparation can be found in U.S.Pat. Nos. 4,208,314, 3,383,351 (Re. 28,715), 3,304,273, 3,652,639, and3,823,201 (Re. 29,014), the disclosures of which are hereby incorporatedby reference.

As was previously mentioned, other suitable polyols, which can be usedin the reactive polyol composition of this invention, include thealkylene oxide adducts of organic compounds having at least 2 activehydrogens, such as amines and thiols. The alkylene oxides which areuseful in this regard are the same as those described in connection withthe preparation of polyoxyalkylene polyether polyols.

Suitable thiols which may be reacted with an alkylene oxide includealkane thiols containing at least two --SH groups such as1,2-ethanedithiol, 1,2-propanedithiol, 1,3-propanedithiol, and1,6-hexanedithiol; and alkenethiols such as 2-butene-1,4-dithiol, andalkynethiols such as 3-hexyne-1,6-dithiol.

Suitable polyamines which can be reacted with an alkylene oxide includearomatic polyamines such as methylene dianiline, polyaryl-polyalkylenepolyamine (crude methylene dianiline), p-aminoaniline,1,5-diaminonaphthalene, and 2,4-diaminotoluene; aliphatic polyaminessuch as ethylenediamine, 1,3-propanediamine, 1,4-butanediamine, and1,3-butanediamine, as well as substituted secondary derivatives thereof.

As was previously mentioned, hydroxy-terminated polyacetals may also beused as polyols in accordance with this invention. These may beprepared, for example, by the reaction of formaldehyde or other suitablealdehyde with a dihydric alcohol or an alkylene oxide such as thosepreviously described.

The mixture of polymer dispersion and compound containing at least twoactive hydrogen atoms is used to prepare polyurethane elastomers. Inorder to prepare polyurethane elastomers, the mixture is reacted withany conventional organic polyisocyanate, modified organicpolyisocyanate, or quasi prepolymer, as well as mixtures thereof.Representative conventional organic polyisocyanates correspond to thefollowing formula:

    R"(NCO).sub.z

wherein R" is a polyvalent organic radical which is either aliphatic,aralkyl, alkaryl, aromatic or mixtures thereof, and z is an integerwhich corresponds to the valence of R" and is at least two.Representative of the organic polyisocyanates contemplated hereininclude, for example, aromatic diisocyanates such as 2,4-toluenediisocyanate, 2,6-toluene diisocyanate, mixtures of 2,4- and 2,6-toluenediisocyanate, crude toluene diisocyanate, 4,4'-diphenylmethanediisocyanate, 2,4'-diphenylmethane diisocyanate, mixtures of 4,4'- and2,4'-diphenylmethane diisocyanate, polymethylene polyphenyl isocyanates,mixtures of diphenylmethane diisocyanates and polymethylene polyphenylpolyisocyanates, and the like; aromatic triisocyanates such as4,4',4"-tri-phenylmethane triisocyanate, 2,4,6-toluene triisocyanates;aromatic tetraisocyanates such as4,4'-dimethyldiphenylmethane-2,2',5,5'-tetraisocyanate, and the like;arylalkyl polyisocyanates such as xylene diisocyanate; aliphaticpolyisocyanates such as hexamethylene-1,6-diisocyanate, lysinediisocyanate methylester and the like, and mixtures thereof. Otherorganic polyisocyanates include hydrogenated methylenediphenylisocyanate, m-phenylene diisocyanate,naphthalene-1,5-diisocyanate, 1-methoxyphenylene-2,4-diisocyanate,4,4'-biphenylene diisocyanate, 3,3'-dimethoxy-4,4'-biphenyldiisocyanate, 3,3'-dimethyl-4,4'-biphenyl diisocyanate, and3,3'-dimethyldiphenylmethane-4,4'-diisocyanate. These polyisocyanatesare prepared by conventional methods known in the art such as thephosgenation of the corresponding organic amine.

As was mentioned, isocyanates which are modifications of the aboveisocyanates which contain carbodiimide, allophanate or isocyanuratestructures may also be used. Quasi-prepolymers may also be employed.These quasi-prepolymers are prepared by reacting an excess of organicpolyisocyanate or mixtures thereof with a minor amount of an activehydrogen-containing compound as determined by the well-knownZerewitinoff test, as described by Kohler in Journal of the AmericanChemical Society, Vol. 49, page 3181 (1927). These compounds and theirmethods of preparation are well known in the art. The use of any onespecific active hydrogen compound is not critical hereto, rather anysuch compound can be employed herein. Generally, the quasi-prepolymershave a free isocyanate content of from 20 percent to 40 percent byweight.

In addition to the previously described ingredients, other ingredientssuch as surfactants, fillers, pigments, blowing agents, and catalystscan be included in the preparation of the polyurethane elastomers. Theseingredients are usually added to the polyol before reaction with theorganic isocyanate to form a resin component which is then reacted withthe isocyanate component.

Surfactants which can be used include polyoxyalkylene derivatives ofsiloxane or the alkylene oxide adducts of organic compounds containingreactive hydrogen atoms such as the ethylene oxide adducts of alcohols,glycols and phenols. Generally, the surfactants are employed in amountsranging from about 0.01 part to 5 parts by weight per 100 parts ofpolyol.

Conventional fillers for use herein include, for example, aluminumsilicate, calcium silicate, magnesium silicate, calcium carbonate,barium sulfate, calcium sulfate, glass fibers, flaked glass, carbonblack, and silica. The filler, if used, is normally present in an amountranging from about 5 parts to 50 parts by weight per 100 parts of resin.

A pigment which can be used herein can be any conventional pigmentheretofore disclosed in the art such as titanium dioxide, zinc oxide,iron oxide, antimony oxide, chrome green, chrome yellow, iron bluesiennas, molybdate oranges, and organic pigments such as para reds,benzidine yellow, toluidine red, toners, and phthalocyanines.

Conventional blowing agents such as halohydrocarbons, hydrocarbons andthe like, can be employed herein in their conventional mode.Representative examples include halogenated hydrocarbons such asmonochlorodifluoromethane, dichloromonofluoromethane,dichlorodifluoromethane, and trichlorofluoromethane, and hydrocarbonssuch as propane and isobutane.

Any of the catalysts employed in the preparation of polyurethane foamcan be employed in the subject invention. Representative of thesecatalysts include the tertiary amine catalysts such asdiethylenetriamine, ketimine, tetramethylenediamine, triethylenediamine,tetramethylenediamine, tetramethylguanidine, trimethylpiperazine and themetalo-organic salt catalysts which are polyvalent metal salts of anorganic acid having up to about 18 carbon atoms and being void of activehydrogen atoms. The organo portion of the salt may be either linear orcyclic or saturated or unsaturated. Generally, the polyvalent metal hasa valence from about 2 to 4. Typical of these salts include: stannousacetate, stannous butyrate, stannous 2-ethylhexoate, stannous laurate,stannous oleate, stannous stearate, stannous octoate, leadcyclopentanecarboxylate, cadmium cyclohexanecarboxylate, leadnaphthenate, lead octoate, cobalt naphthenate, zinc naphthenate,bis(phenylmercury)dodecyl succinate, phenylmercuric benzoate, cadmiumnaphthenate, dibutyltin dilaurate and dibutyltin-di-2-ethylhexanoate.Generally these catalysts will be employed in amounts ranging from about0.01 part to 7.5 parts by weight based on the weight of the compoundhaving an average molecular weight of 1000 to 8000 containing two ormore active hydrogen atoms.

In general, the polyurethane elastomers of the present invention areprepared by mixing together the ingredients mechanically and/or by theuse of high pressure machinery. The ratio of ingredients is such thatfrom 0.7 equivalent to 1.4 equivalents of isocyanate is present perequivalent of active hydrogen contained in the active hydrogencontaining compound having a molecular weight of 1000 to 8000 and thechain extender. Preferably from 0.9 equivalent to 1.15 equivalents ofisocyanate is present per equivalent of active hydrogen atom. As waspreviously mentioned, the polyol compositions described herein for thepreparation of polyurethane-polyurea elastomers are particularly usefulfor the preparation of molded products by reaction injection moldingtechniques.

The Examples which follow will illustrate in more detail the practice ofthis invention. They are not intended to limit the scope of itsapplication. The parts referred to in the Examples are by weight unlessotherwise specified, and the temperatures are in degrees centigradeunless otherwise specified. The following abbreviations will be used inthe examples which follows:

AN--acrylonitrile

BDO--1,4-butanediol

DABCO 33LV--33 percent by weight of triethylene diamine in dipropyleneglycol, a catalyst.

PVP--polyvinyl pyrolidone having an average molecular weight of 40,000unless otherwise stated.

STY--styrene

Polymerization initiator--2-t-butylazo-2-cyanobutane

Isocyanate No. 1--a mixture of quasi-prepolymer based upon pure MDIhaving a free NCO content of 25 percent by weight

T-12--dibutyltin dilaurate, a catalyst

Polyol A--a polyoxyalkylene polyether polyol having an average molecularweight of 5140 prepared by the oxyalkylation of trimethylolpropane

Polyol B--a polyoxyalkylene polyether polyol having an average molecularweight of 4146 prepared by the oxyalkylation of glycerin.

EXAMPLE 1

Into a four-neck reaction vessel equipped with a stirrer, thermometer,nitrogen inlet, water cooled condenser, and inlet tube was charged 825parts of 1,4-butanediol and 75 parts of PVP. The mixture was heated to115° C. A stream consisting of 600 parts of acrylonitrile and 600 partsof styrene were then added to the vessel along with another streamconsisting of 900 parts of 1,4-butanediol and 24 parts of2-t-butylazo-2-cyanobutane. The monomers were added over 4 hours whilethe BDO-polymerization initiator mixture was added over 4 hours, 10minutes. The reaction time was 30 minutes and the stirrer was operatedat 300 rpm.

After completion of the reaction, the reaction mixture was vacuumstripped for 45 minutes at 80° C. and 1 mm Hg. The white dispersion hada Brookfield viscosity (25° C.) of 1580 cps (39.1 percent vinyl polymercontent).

EXAMPLES 2-17

Examples 2-17 were prepared in a manner similar to Example 1. Thespecific ingredients and other variables along with the Brookfieldviscosity are set forth in Table I which follows.

                                      TABLE I                                     __________________________________________________________________________                                       Monomer                                                                  Reaction                                                                           Addn.                                      PVP      BDO, p.         Catalyst                                                                           Temp.                                                                              Time  Stripping                                                                          Viscosity                       Example                                                                            Charge                                                                            Charge                                                                            Feed                                                                             AN, p.                                                                            STY, p.                                                                            p.   °C.                                                                         min.  Loss, p.                                                                           cps./25° C.              __________________________________________________________________________     2   40  140 180                                                                              120 120  4.8  115  180   15.6 6540                             3   24  156 180                                                                              120 120  4.8  115  180   15.2 2740                             4   15  165 180                                                                              120 120  4.8  115  180   15.3 1400                             5   15  165 180                                                                              120 120  4.8  120  180   21.6 1560                             6   10  170 180                                                                              120 120  4.8  115  180   13.3 1020                             7   15  165 180                                                                              120 120  4.8  115  240   13.7 1500                             8   15  165 180                                                                              120 120  8.8  115  165   18.2 1600                             9   15  165 180                                                                               60 180  4.8  115  185   7.0  1400                            10   15  165 180                                                                              160  80  4.8  115  180   19.8 1450                            11   15  165 180                                                                               80 160  4.8  115  180   13.9 1630                            12   15  165 180                                                                              180  60  4.8  115  180   19.0 1170                            13   12  168 180                                                                              120 120  4.8  115  240   16.6 1140                            14   75  825 900                                                                              600 600  24.0 115  240   47.8 1580                            15   .sup. 15.sup.a                                                                    165 180                                                                              120 120  4.8  115  180   13.8  850                            16   15  165 180                                                                              120 120  4.8  115  180   14.8 1570                            17   15  .sup. 165.sup.b                                                                   180                                                                              120 120  4.8  115  180   52.2  870                            __________________________________________________________________________     .sup.a PVP, 10,000 MW                                                         .sup.b Ethylene glycol                                                   

EXAMPLE 18

A polyurethane plaque was prepared as a prototype of a microcellularreaction injection molded foam. The foam was prepared in a 10"×10"×1/8"mold which was cleaned, dried and heated to 145° F. in an oven(temperature of mold checked with infrared thermometer). A mold releaseagent was sprayed on the hot mold before the addition of handmixedmaterial.

The resin side of the microcellular foam including polyol, BDOdispersion, amine catalyst and tin catalyst were mixed at high speed for60 seconds, allowed to stand for 60 seconds and then the required amountof isocyanate was added. The mixture was stirred for 5 to 10 seconds,added to the hot mold and closed. The mold was opened 2 minutes laterand the plaque removed. The plaques were further cured at 120° C. for 30minutes. The specific ingredients and the properties of the resultingplaque are shown in Table II which follows.

                  TABLE II                                                        ______________________________________                                                        Parts                                                         ______________________________________                                        Formulation                                                                   Polyol A          45.2                                                        Polyol B          45.2                                                        BDO of Example 14 59.4                                                        DABCO 33LV        1.8                                                         T-12              0.05                                                        Isocyanate No. 1* 158                                                         Index             105                                                         Physical properties**                                                         Density, pcf      54.1                                                        Tensile strength, psi                                                                           1480                                                        Elongation, %     20                                                          Graves Tear, pi   266                                                         Hardness Shore D  53                                                          Heat sag, 250° F.                                                                        0.56                                                        ______________________________________                                         *Insufficient isocyanate may have been used due to container                  **Sample was postcured 30 minutes at 120° C.                      

The embodiments of the invention in which an exclusive privilege orproperty is claimed are defined as follows:
 1. A mixture comprising(a) apolymer dispersion prepared by the in situ polymerization of about 10percent to about 70 percent by weight based upon the total weight of thedispersion of an ethylenically unsaturated monomer or mixture ofmonomers in a chain extender of a molecular weight of 62 to less than400 selected from the group consisting of aliphatic and/or araliphaticdiols having 2 to 14 carbon atoms in the presence of a free radicalpolymerization initiator and a polyamide stabilizer having a pendentamide group said polyamide having an average molecular weight of fromabout 5000 to about 1,000,000, wherein the weight ratio of the monomerto the polyamide is form about 2:1 to about 100:1; and (b) a compoundcontaining two or more active hydrogen atoms as determined by theZerewitinoff method with a molecular weight of 1000 to
 8000. 2. Themixture of claim 1 wherein (b) is selected from the group consisting ofpolyoxyalkylene polyols and graft polyoxyalkylene polyols.
 3. Themixture of claim 2 wherein the polyamide has an average molecular of10,000 to 60,000.
 4. The mixture of claim 3 wherein the polyamide ispoly(N-vinyl-2-pyrrolidone).
 5. The mixture of claim 4 wherein the chainextender is selected from the group consisting of 1,4-butanediol andethylene glycol.
 6. The mixture of claim 5 wherein the monomer is amixture of acrylonitrile and styrene.
 7. The mixture of claim 6 whereinthe weight ratio of acrylonitrile to styrene is from 3:1 to 1:3.
 8. Themixture of claim 7 wherein the weight ratio of monomer mixture topoly(N-vinyl-2-pyrrolidone) is from about 10:1 to about 24:1.
 9. Themixture of claim 8 wherein the weight ratio of vinyl polymer is fromabout 10 percent to about 70 percent by weight based upon the totalweight of the dispersion.